关键词: 超声检查, 下尿路症状, 膀胱出口梗阻, 前列腺

Abstract: ［Abstract］ Objective To evaluate the predictable effect of prostatic urethra length（PU）on bladder outlet obstruction（BOO）in patients with low urinary tract symptoms（LUTS）basing on investigating the correlation between PU segmental length，prostatic volume （PV），residual urine （RU） and BOO. Methods Clinical data of 168 outpatients or hospitalized males with LUTS were collected from January 2014 to June 2017. PU，superior prostatic urethra length （SPU），inferior prostatic urethra length （IPU），ratio of SPU and IPU（SIR），PV were measured and calculated by transrectal ultrasonography. The residual urine（RU）was measured and calculated by transabdominal ultrasonography. Bladder outlet obstruction index（BOOI）was recorded by uroflowmetry. BOO was defined by a BOOI above 40. Firstly， the data were divided into two groups accordingly BOOI≥40 and BOOI<40. Statistical significance of mean value was compared between two groups. Correlation was analyzed between BOOI and PU ，SPU， IPU，SIR，PV，RU and age. Univariate analysis was used to screen the risk factors of BOO. Receiver operating characteristic curves （ROC） were used to evaluate PU， SPU， IPU， SIR， PV， RU in predicting BOO in patients with LTUS. Results The proportion of BOO was 58.9%（99/168）in our study. BOO in LUTS patients correlated positively with SIR，SPU，RU，PU，PV（r=0.427，P=0.001；r= 0.387，P=0.027；r=0.313，P=0.019；r=0.308，P=0.032；r=0.269，P=0.038），whereas uncorrelated with IPU and age（r=0.159，P=0.147；r=0.118，P=0.063，respectively）. The positive predictive value of SIR took up the highest percentage amongst these parameters（75.2%，76/101）. Significant difference of SIR was found between the groups of BOOI≥40 and BOOI<40 in LTUS patients（t=3.856，P=0.002）. The incidence rate of the BOO was higher in group of SIR≥1.5 than that of SIR<1.5（?2=20.563，P< 0.001）. The area under curve（AUC）of the ROC of SIR in predicting BOO in LTUS patients was 0.729± 0.061（P=0.002），and optimal cut-off value was SIR≥1.5. The parameter of SIR≥1.5 could predict presence of BOO in LUTS patients with a sensitivity of 66.8% and specificity of 90.1% . Conclusion SIR，SPU，PU，RU，PV positively correlate with the incidence of BOO in patients with LUTS.SIR manifests a better predictor over these parameters. Patients with SIR≥1.5 are at a higher risk for BOO than those with SIR<1.5 with a favorite specificity and fairly sensitivity.

Key words: prostate, ultrasonography, lower urinary tract symptoms, bladder outlet obstruction